unlocking objects which was locked and saved before
At the top right of the Outliner there is a "Filters" button (it looks like a small funnel).

Click on that, and at the top of the tab that appears you have "Restriction Toggles". You want to turn on the "Selectable" toggle, which is the second button in the row.

Once you do that, you will be able to mark objects as able to be selected or not able to be selected just like you did before they updated the 2.8 interface.

You can also do the same thing to restore the options for render visibility and globally disable in viewports if you want them too.